What is a square root?
The square root of a number n is a value that produces n when multiplied by itself. For example, the square root of 49 is 7 because 7 × 7 = 49.
How to calculate a square root
Enter the number and select Calculate. The calculator gives the decimal square root and checks that squaring the result returns the original input, within normal numerical precision.
Square root formula
Basic definition
√n = x when x² = n
Examples
√144 = 12
√25 = 5
√12 = 2√3 ≈ 3.4641
Racine carrée calculator and French variations
People may also search for this tool using phrases such as racine carree calculator, calcul racine carree, or calculatrice racine carree. These are wording variations for the same square-root calculation, so they belong on this page rather than separate duplicate pages.
Frequently asked questions
What is the square root of a perfect square?
A perfect square has an integer square root. For example, √100 = 10.
Can I enter a decimal?
Yes. The calculator accepts decimal values as well as whole numbers.
Can I calculate the square root of a negative number?
This calculator focuses on real square roots, so negative inputs are rejected. A negative number has no real square root.
What is the square root symbol?
The symbol √ is called the radical sign. The expression √n means the principal square root of n.